• English Language & Literature Teaching
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• v.15 no.3
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• pp.1-31
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• 2009

Although Korean university students' primary concern is academic success in their higher degrees in the UK, they highly desire to develop English communicative competence through a number of opportunities to speak with natives speakers. The paper aims at examining to what extent they are able to be socialised into a new environment while they are studying at UK universities. The in-depth, longitudinal interviews with the targeted group of six Korean masters' students at the University of York was undertaken to observe the pace of their progress in developing social skills. Reluctance and hesitance to contact and interact with their supervisors and other academic staff persisted for most of them to the final term caused by cultural reasons such as face and hierarchy rather than language problems. Despite the six participants' variation in their patterns of social interaction, they struggled with pressures towards monoculture-biased interaction with Korean people, which was quite extreme for the five participants. This passivity can be explained by several reasons such as the students' lack of communicative competence and other situational factors on one-year course. It is important to note that students' failure to develop network with native speakers is strongly associated with experience of cultural withdrawal and frustration with developing communicative competence in English.

• Nuclear Engineering and Technology
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• v.53 no.10
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• pp.3264-3274
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• 2021

In a severe accident of light water reactor (LWR), molten core material (corium) can be released into the wet cavity, and a fuel-coolant interaction (FCI) can occur. The molten jet with high speed is broken and fragmented into small debris, which may cause a steam explosion or a molten core concrete interaction (MCCI). Since the premixing stage where the jet breakup occurs has a large impact on the severe accident progression, the understanding and evaluation of the jet breakup phenomenon are highly important. Therefore, in this study, the jet breakup simulations were performed using the Smoothed Particle Hydrodynamics (SPH) method which is a particle-based Lagrangian numerical method. For the multi-fluid system, the normalized density approach and improved surface tension model (CSF) were applied to the in-house SPH code (single GPU-based SOPHIA code) to improve the calculation accuracy at the interface of fluids. The jet breakup simulations were conducted in two cases: (1) jet breakup without structures, and (2) jet breakup with structures (control rod guide tubes). The penetration depth of the jet and jet breakup length were compared with those of the reference experiments, and these SPH simulation results are qualitatively and quantitatively consistent with the experiments.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.319-324
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• 2019

A depth-encoding detector module with silicon photomultipliers(SiPMs) using two layers of scintillation crystal array was designed, and the position measurement capability was verified using DETECT2000. The depth of interaction of the crystal pixels with the gamma rays was tracked through the image acquired with the combination of surface treatment of the crystal pixels and reflectors. The bottom layer was treated as a reflector except for the optically coupled surfaces, and the crystals of top layer were optically coupled each other except for the outer surfaces so that the light sharing was made easier than the bottom layer. Flood images were obtained through the combination of specular reflectors and random reflectors, grounded and polished surfaces of crystal pixels, and the positions at which layer images were generated were measured and analyzed. The images were reconstructed using the Anger algorithm, whose the SiPM signals were reduced as the 16-channels to 4-channels. In the combination of the grounded surface and all reflectors, the depth positions were discriminated into two layers, whereas it was impossible to separate the two layers in the all polished surface combinations. Therefore, using the combination of grounded surface crystal pixels and reflectors could improve the spatial resolution at the outside of the field of view by measuring the depth position in preclinical positron emission tomography.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.2
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• pp.160-176
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• 2017

The interaction of focused wave groups with a vertical wall is investigated based on the second order potential theory. The NewWave theory, which represents the most probable surface elevation under a large crest, is adopted. The analytical solutions of the surface elevation, velocity potential and wave force exerted on the vertical wall are derived, up to the second order. Then, a parametric study is made on the interaction between nonlinear focused wave groups and a vertical wall by considering the effects of angles of incidence, wave steepness, focal positions, water depth, frequency bandwidth and the peak lifting factor. Results show that the wave force on the vertical wall for obliquely-incident wave groups is larger than that for normally-incident waves. The normalized peak crest of wave forces reduces with the increase of wave steepness. With the increase of the distance of focal positions from the vertical wall, the peak crest of surface elevation, although fluctuates, decreases gradually. Both the normalized peak crest and adjacent crest and trough of wave forces become larger for shallower water depth. For focused wave groups reflected by a vertical wall, the frequency bandwidth has little effects on the peak crest of wave elevation or forces, but the adjacent crest and trough become smaller for larger frequency bandwidth. There is no significant change of the peak crest and adjacent trough of surface elevation and wave forces for variation of the peak lifting factor. However, the adjacent crest increases with the increase of the peak lifting factor.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.33-39
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• 1991

This experiment was carried out in order to study the changes of morphological characters of growth and thatch accumulation in perennial ryegrass as affected by the different levels of soil compaction and coring depth. Soil compactions were treated with 10, 20, 30 and 40kg power roller and artificial core depth were 2.5, 5.0, 7.5 and 10.0cm under the ground, respectively. And, artificial core space were fixed 84.5% in all soil compaction levels. The results obtained were summarized as follows: 1. Relationship between number of tillers and root weight was positive significant difference for soil compaction levels. 2. Relationships between shoot dry weight and thatch weight, and number of tillers were positively significant difference for artificial core depths. It may indicate that thatch accumulation depend on the growth of shoot, and increase of shoot dry weight as growth progressed may due to increase of number of tillers, respectively. 3. Soil compaction level of 20kg was greatly influenced on the growth of shoot in all artificial soil depths. Thus, shoot dry weight and number of tillers were obtained the highest value, but thatch and root weight were obtained the lowest values at the soil compaction level of 20kg. It was suggested that soil compaction of 20kg is very suitable rolling factor for turf maintenance. 4. Thatch weight was positively significant difference for the interaction of soil compaction levelXcoring depth.5. Thatch weight was positive significant correlated with root weight, and negative significant correlated with number of tillers by increase of soil compaction levels.

• Computers and Concrete
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• v.20 no.4
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• pp.429-437
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• 2017

In this study, the effect of the tensile strength and ratio of disc spacing to penetration depth on the efficiency of tunnel boring machine (TBM) is investigated using Particle flow code (PFC) in two dimensions. Models with dimensions of $150{\times}70mm$ made of rocks with four different tensile strength values of 5 MPa, 10 MPa, 15 MPa and 20 MPa were separately analyzed and two "U" shape cutters with width of 10 mm were penetrated into the rock model by velocity rate of 0.1 mm/s. The spacing between cutters was also varied in this study. Failure patterns for 5 different penetration depths of 3 mm, 4 mm, 5 mm, 6 mm, and 7 mm were registered. Totally 100 indentation test were performed to study the optimal tool-rock interaction. An equation relating mechanical rock properties with geometric characteristics for the optimal TBM performance is proposed. The results of numerical simulations show that the effective rock-cutting condition corresponding to the minimum specific energy can be estimated by an optimized disc spacing to penetration depth, which, in fact, is found to be proportional to the rock's tensile strength.

• Structural Engineering and Mechanics
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• v.83 no.5
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• pp.671-680
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• 2022

The shear capacity of beams is an essential parameter in designing beams carrying shear loads. Precise estimation of the ultimate shear capacity typically requires comprehensive calculation methods. For steel fiber reinforced concrete (SFRC) beams, traditional design methods may not accurately predict the interaction between different parameters affecting ultimate shear capacity. In this study, artificial neural network (ANN) modeling was utilized to predict the ultimate shear capacity of SFRC beams using ten input parameters. The results demonstrated that the ANN with 30 neurons had the best performance based on the values of root mean square error (RMSE) and coefficient of determination (R²) compared to other ANN models with different neurons. Analysis of the ANN model has shown that the clear shear span to depth ratio significantly affects the predicted ultimate shear capacity, followed by the reinforcement steel tensile strength and steel fiber tensile strength. Moreover, a Genetic Algorithm (GA) was used to optimize the ANN model's input parameters, resulting in the least cost for the SFRC beams. Results have shown that SFRC beams' cost increased with the clear span to depth ratio. Increasing the clear span to depth ratio has increased the depth, height, steel, and fiber ratio needed to support the SFRC beams against shear failures. This study approach is considered among the earliest in the field of SFRC.

• Journal of The Korean Association of Information Education
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• v.9 no.3
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• pp.501-510
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• 2005

To facilitate interaction between home robot and humans, it's urgently needed to make in-depth research in Human-Robot Interaction(HRI). The purpose of this study was to examine how children interacted with a newly developed home robot named 'iRobi' in a bid to identify how the home robot affected their psychology and the effectiveness of learning through the home robot. Concerning the psychological effects of the home robot, the children became familiar with the robot, and found it possible to interact with it, and their initial anxiety was removed. As to its learning effect, the group that studied by using the home robot outperformed the others utilizing the other types of learning media (books, WBI)in attention, learning interest and academic achievement. Accordingly, home robot could serve as one of successful vehicles to expedite the psychological and educational interaction of children.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.3
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• pp.251-260
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• 2021

Purpose: This study uses a descriptive research design to identify the influence of critical thinking disposition, deep approaches to learning, and interaction between learners on the degree of nursing process confidence for nursing students. Methods: The subjects of the study were second-year students in the Department of Nursing at a university in G city. The data included general characteristics, critical thinking disposition, deep approaches to learning, learner-to-learner interaction, and nursing process confidence were analyzed utilizing an independent t-test, one-way ANOVA, and Scheffe's test to identify differences in the variables according to general characteristics. To identify the correlation between the factors related to the nursing process and nursing process confidence, Pearson's correlation was analyzed, and hierarchical regression was used to determine the factors affecting the confidence of the subject's nursing process. Results: Gender, critical thinking disposition, and in-depth learning approach were statistically significant as factors affecting the nursing process confidence of nursing students, and these factors were shown to explain 62% of nursing course performance (F=23.80, p<.001), among which in-depth learning access has the greatest influence (β=.41, p<.001). Conclusion: Critical thinking disposition and deep approaches to learning arbitration program development are necessary to improve nursing students' nursing process confidence.

• Geomechanics and Engineering
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• v.30 no.4
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• pp.383-392
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• 2022

Although pipelines are composed of segmental tubes commonly connected by rubber gasket or push-in joints, current studies mainly simplified pipelines as continuous structures. Effects of joints on three-dimensional deformation mechanisms of existing pipelines due to tunnel excavation are not fully understood. By conducting three-dimensional numerical analyses, effects of pipeline burial depth, tunnel burial depth, volume loss, pipeline stiffness and joint stiffness on bending strain and joint rotation of existing pipelines are explored. By increasing pipeline burial depth or decreasing tunnel cover depth, tunneling-induced pipeline deformations are substantially increased. As tunnel volume loss varies from 0.5% to 3%, the maximum bending strains and joint rotation angles of discontinuous pipelines increase by 1.08 and 9.20 times, respectively. By increasing flexural stiffness of pipe segment, a dramatic increase in the maximum joint rotation angles is observed in discontinuous pipelines. Thus, the safety of existing discontinuous pipelines due to tunnel excavation is controlled by joint rotation rather than bending strain. By increasing joint stiffness ratio from 0.0 (i.e., completely flexible joints) to 1.0 (i.e., continuous pipelines), tunneling-induced maximum pipeline settlements decrease by 22.8%-34.7%. If a jointed pipeline is simplified as a continuous structure, tunneling-induced settlement is thus underestimated, but bending strain is grossly overestimated. Thus, joints should be directly simulated in the analysis of tunnel-soil-pipeline interaction.